The present invention relates to a vertical rolling mill which is provided with at least a pair of rolling rolls having vertical axes of rotation.
To explain the conventional rolling mills of this type reference is made to a rolling mill 31 shown in FIG. 1 as an example. A pair of spindle members 33 and 33' are connected to a driving member 32 and said spindle members are disposed directly above a stand 35 provided with a pair of rolling rolls 34 and 34'. The spindle members 33 and 33' are respectively connected with the rolling rolls 34 and 34' so as to drive them from above. Therefore, in the case of this rolling mill 31, at the time of replacing the stand 35, it is impossible to perform said replacing by lifting same with a machine, such as crane, etc., unless the stand 35 is shifted from the prescribed position for rolling indicated by the solid line to one side as indicated by the dotted line because the spindle members 33 and 33' obstruct it. Accordingly, provision of a mechanism 36 for the purpose of thus shifting the stand 35 sideways is indispensable. Besides, since much time is required in the work of replacing the stand 35, as stated above, in order to reduce the frequency of replacing, multicaliber-type rolls 34 and 34' provided with plural number of calibers for inserting the material-to-be-rolled have been adopted. Because of the adoption of this multicaliber-type roll, provision of a mechanism 37 for effecting vertical movement of the stand 35 in order to align all the calibers with the pass line appropriately is indispensable. Inasmuch as the rolling mill 31 is provided with the mechanisms 36 and 37 as stated above, it becomes large in size, complicated in structure and heavy in weight as a whole, necessitating a large-size foundation at the time of erecting it, and also a spacious site is required therefore. Accordingly, it is difficult to erect this rolling mill 31 among existing various machines for the rolling process in factories. Moreover, inasmuch as the stand 35 per se having said multicaliber-type rolls 34 and 34' is heavy in weight, the machine for use in lifting it, e.g., crane, etc., must be of a large size. The upper end of a lifting machine such as a large-sized crane and the like at the time of operation is close to the restricted height of factory buildings, and therefore it must be operated with prudence. Consequently, the work of replacing the stand 35 is inconvenient and is difficult to perform.
As set forth above, the conventional rolling mills exemplified by the rolling mill 31 illustrated in FIG. 1 have been accompanied by various drawbacks such as enumerated in the foregoing.